TECHNICAL MANUALOPERATORS MANUAL

FORARMY MODEL

AH-1FATTACK HELICOPTER

*TM 1-1520-236-10

HEADQUARTERS, DEPARTMENT OF THE ARMY26 JANUARY 2001

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

*This manual supersedes TM 55-1520-236-10, dated 11 January 1980 including all changes.

WARNING DATA

NORMAL PROCEDURES

EMERGENCY PROCEDURES

REFERENCES

ABBREVIATIONS AND TERMS

ALPHABETICAL INDEX

DESCRIPTION AND OPERATION

INTRODUCTION

OPERATING LIMITS ANDRESTRICTIONS

WEIGHT/BALANCE AND LOADING

MISSION EQUIPMENT

AVIONICS

PERFORMANCE DATAB540

PERFORMANCE DATAK747

TABLE OF CONTENTS

TM 1-1520-236-10

a

WARNING

Personnel performing operations, procedures, and practices which are included or implied inthis manual shall observe the following warnings. Disregard of these warnings and precaution-ary information can cause serious injury or loss of life. Procedures outlined in paragraph 1-6,AR 40-46 are applicable.

The M-65 Laser Range Finder is very dangerous. Looking at the laser beam or its reflection froma shiny surface can cause permanent blindness. Under non-combat conditions, the laser shallbe used only in controlled areas and at times specified by a range control officer. The laser filterin the telescopic sight shall be used in any area where lasers are in use.The AIM-1/EXL Laser is very dangerous. Looking at the laser beam or its reflection from a shinysurface can cause permanent blindness. Ensure that the laser protective cover is kept over theemitter and that the AIM power switch is off at all times when laser is not in use. Under non-com-bat conditions, the laser shall be used only in controlled areas and at times specified by a rangecontrol officer. Night goggles are required during operation and boresight procedures.

STARTING ENGINE

Coordinate all cockpit actions with ground observer. Ensure that rotors and blast area are clearand fire guard is posted.

GROUND OPERATION

Engine will be started and helicopter operated only by authorized personnel. Reference AR95-1.

GROUNDING HELICOPTER

The helicopter should be electrically grounded when parked and will be grounded during re-fueling operations.

TM 1-1520-236-10

b

FIRE EXTINGUISHER

Exposure to high concentrations of monobromotrifluoromethane (CF3Br) extinguishing agentor decomposition products should be avoided. The agent should not be allowed to come intocontact with the skin, as it may cause frostbite or low-temperature burns.When helicopter is to be parked where ambient temperature equals or exceeds 90F (32C), thefire extinguisher shall be removed until the next mission.Should an extinguisher be left in the helicopter inadvertently during a high temperature period,the extinguisher shall be weight checked prior to the next mission.

ARMAMENT

Prior to loading or unloading 2.75 inch rockets, the wing stores power circuit breaker will bepulled.Loaded weapons, or weapons being loaded or unloaded, shall be pointed in a direction whichoffers the least exposure to personnel or property in the event of an accidental firing. Person-nel should remain clear of a hazardous area (forward or aft) of all loaded weapons. Rocket igni-ter arms shall remain in contact with rockets, when loaded, to reduce possibility of ignition dueto EMI (electromagnetic interference).During ground operations, when servicing the turret, the TUR SLEW switch shall be placed inGND TEST position to prevent injury to ground operations servicing personnel. Ground opera-tions servicing personnel shall be clear of dangerous areas prior to any weapons system opera-tion.

All ground run armament checks should be accomplished with the TUR SLEW rate switch inthe GND TEST position to prevent any possibility of injuries inflicted on maintenance person-nel working in the proximity of the operating aircraft and the turret area.

CANOPY REMOVAL SYSTEM

Ground safety pins shall be installed in pilot and gunner canopy removal arming/firing mecha-nisms when the helicopter is on the ground. Pilot safety pin shall be removed prior to flight.Safety pins shall be installed during engine shutdown check. Debris may be expelled 50 feetoutward when system is actuated. Pilot and gunner helmet visor should be down to preventeye injury.

VERTIGO

The rotating beacon light should be turned off during flight through clouds to prevent sensa-tion of vertigo as a result of reflections of the light on the clouds.

CARBON MONOXIDE

When smoke, suspected carbon monoxide fumes, or symptoms of anoxia exist, the crewshould immediately ventilate cockpits.

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c

FUEL, OIL AND HYDRAULIC FLUIDS

Turbine fuels and lubricating oils contain additives which are poisonous and readily absorbedthrough the skin. Do not allow them to remain on skin longer than necessary. Prolonged con-tact may cause a skin rash. Prolonged contact with hydraulic fluid will cause burns. Refer toFM 10-68 when handling fuel.When handling hydraulic fluid (MIL-H-83282), observe the following: - Prolonged contact with liquid or mist can irritate eyes and skin. - After any prolonged contact with skin, immediately wash contacted area with soap and water. If liquid contacts eyes, flush them immediately with clear water. - If liquid is swallowed, do not induce vomiting, get immediate medical attention. - Wear rubber gloves when handling liquid. If prolonged contact with mist is likely, wear an appropriate respirator.

- When fluid is decomposed by heating, toxic gases are released.

ELECTROLYTE

Battery electrolyte is harmful to the skin and clothing. If potassium hydroxide is spilled onclothing or other material, wash immediately with clean water. If spilled on personnel, immedi-ately start flushing the affected area with clean water. Continue flushing until medical assis-tance arrives.

ROTOR BLADES

Personnel shall stay clear of turning main and tail rotor blades. Wind gusts, coast down, orcyclic movement may cause the main rotor blade to flap down below the height of a person.Dangerous winds are created by the main rotor blades when blades are at operating rpm.

NOISE LEVEL

Sound pressure levels in the helicopter during some operating conditions exceed the SurgeonGenerals hearing conservation criteria as defined in TB MED 251. Hearing protection devices,such as the aviator helmet, ear plugs, or ear muffs shall be worn by all personnel in and aroundthe helicopter during operation.

WING STORES JETTISON

All jettison safety pins shall be installed when the helicopter is on the ground. Serious injurycan result from accidental ground jettison. Safety pins shall be removed prior to flight. Failureto do so will prevent emergency jettison of wing stores.

TURRET

When battery power is applied, the turret gun may stow at a very rapid rate and cause personnelinjury.

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d

HIGH VOLTAGE

Serious burns and/or electrical shock can result from contact with exposed electrical wire orconnections.

RADIOACTIVE MATERIALS

Self-luminous dials contain radioactive materials. If such an instrument is broken or becomesunsealed, avoid personnel contact.

TOW MISSILE FIRING

During night TOW missile firing, AN/AVS6 NVGs should be utilized due to the increased mar-gin of safety provided when compared to the AN/PVS5 NVGs.Electromagnetic Interference (EMI) can interfere with missile guidance. Avoidance require-ments are contained in HIRTA messages. Pilots shall be briefed and familiar with these require-ments. Firing of TOW missiles in a high EMI area should be avoided if possible.

10

Some of the FLIR optics inside the C-NITE telescopic sight unit (TSU) have a coating that isradioactive. Accidental inhaling or swallowing of this material is hazardous to health. If theC-NITE TSU has been ruptured (by crash damage, etc.), dispose of broken optics in accor-dance with AR 775-15 and TB 750-237.

WARNING

RADIATION HAZARDThorium Fluoride

NOTE: The portion of the text affected by the changes is indicated bya vertical line in the outer margins of the page. Changes toillustrations are indicated by miniature pointing hands.Changes to wiring diagrams are indicated by shaded areas.

TM 1-1520-236-10

A/(B blank)

Date of issue for original and change pages are: 26 January 2001

Original 0 26 January 2001. . . . . . . . . . . . . . . .

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 372 , CONSISTING OF THE FOLLOWING:

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LIST OF EFFECTIVE PAGES

INSERT LATEST CHANGED PAGES: DESTROY SUPERCEDED PAGES.

*TM 1-1520-236-10

*This manual supersedes TM 55-1520-236-10, dated 11 January 1980, including all changes:i

HEADQUARTERS TECHNICAL MANUAL DEPARTMENT OF THE ARMYNo. 1-1520-236-10 WASHINGTON, D.C., 26 January 2001

TECHNICAL MANUAL

OPERATORS MANUALFOR

ARMY MODELAH-1F

ATTACK HELICOPTER

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTSYou can help improve this manual. If you find any mistakes, or if you know of a way to improve these procedures, pleaselet us know. Mail your letter, DA Form 2028 (Recommended Changes to Publications and Blank Forms) or DA Form2028-2 located in the back of this manual directly to: Commander, U.S. Army Aviation and Missile Command, ATTN:AMSAM-MMC-LS-LP, Redstone Arsenal, AL 35898-5000. A reply will be furnished directly to you.

You may also submit your recommended changes by E-mail directly to ls-lp@redstone.army.mil or by fax (256)842-6546/DSN 788-6546. Instructions for sending an electronic 2028 may be found at the end of this manual immediatelypreceding the hard copy 2028s.

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

TABLE OF CONTENTS

PageCHAPTER 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1CHAPTER 2 HELICOPTER AND SYSTEMS DESCRIPTION AND OPERATION

Section I Helicopter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1II Emergency Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10III Engine and Related Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12IV Helicopter Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19V Flight Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20VI Hydraulic Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22VII Power Train System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23VIII Main and Tail Rotors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24IX Utility System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24X Heating, Ventilation, Cooling and Environmental Control Unit . . . . . . . . . . . . . . 2-26XI Electrical Power Supply and Distribution System . . . . . . . . . . . . . . . . . . . . . . . . . 2-26XII Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30

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ii

TABLE OF CONTENTS (Continued)

XIII Flight Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35XIV Servicing, Parking, and Mooring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39

CHAPTER 3 AVIONICSSection I General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

II Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1III Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21IV Transponder and Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

CHAPTER 4 MISSION EQUIPMENTSection I Mission Avionics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

II Armament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2III Active and Passive Defense Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51

CHAPTER 5 OPERATING LIMITS AND RESTRICTIONSSection I General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

II System Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1III Power Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4IV Loading Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5V Airspeed Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5VI Maneuvering Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7VII Environmental Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7VIII Height Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

CHAPTER 6 WEIGHT/BALANCE AND LOADINGSection I General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

II Weight and Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3III Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3IV Mission Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5V Cargo Loading (Not Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29VI Fuel/Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29VII Allowable Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31

CHAPTER 7 PERFORMANCE DATA B540Section I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

II Performance Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5III Torque Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7IV Hover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12V Cruise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18

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TABLE OF CONTENTS (Continued)

VI Drag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-42VII Climb - Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44VIII Idle Fuel Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-46

CHAPTER 7.1 PERFORMANCE DATA K747Section I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-1

II Performance Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-5III Torque Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-7IV Hover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-12V Cruise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-18VI Drag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-42VII Climb - Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-44VIII Idle Fuel Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-46

CHAPTER 8 NORMAL PROCEDURESSection I Crew Duties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

II Operating Procedures and Maneuvers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4III Instrument Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13IV Flight Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13V Adverse Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19

CHAPTER 9 EMERGENCY PROCEDURESSection I Helicopter Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

II Mission Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11APPENDIX A REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1APPENDIX B ABBREVIATIONS AND TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index 1

iii/(iv blank)

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1-3

CHAPTER 1INTRODUCTION

2-1. GENERAL.These instructions are for use by the operator of theAH-1F helicopter.

2-2. WARNING, CAUTIONS, AND NOTESDEFINITION.Warnings, cautions, and notes are used to emphasizeimportant and critical instructions and are used for thefollowing conditions:

WARNING

An operating procedure, practice, etc.,which, if not correctly followed, couldresult in personal injury or loss of life.

CAUTION

An operating procedure, practice, etc.,which, if not strictly observed could re-sult in damage to or destruction ofequipment.

NOTEAn operating procedure, condition,etc., which it is essential to highlight.

2-3. DESCRIPTION.This manual contains the best operating instructions andprocedures for the AH-1F helicopter under most circum-stances. The observance of limitations, performanceand weight balance data provided is mandatory. The ob-servance of procedure is mandatory except when modifi-cation is required because of multiple emergencies, ad-verse weather, terrain, etc. Your flying experience isrecognized, and therefore, basic flight principles are notincluded. THIS MANUAL SHALL BE CARRIED IN THEHELICOPTER AT ALL TIMES.

2-4. APPENDIX A. REFERENCES.Appendix A is a listing of official publications cited withinthe manual applicable to and available for flight crews.

2-5. APPENDIX B. ABBREVIATIONS ANDTERMS.Appendix B provides a glossary of abbreviations andterms used throughout the text.2-6. INDEX.The index lists, in alphabetical order, every titled para-graph, figure and table contained in this manual. Chap-ters 7 and 7.1 performance data have an additional indexwithin each chapter.

2-7. ARMY AVIATION SAFETY PROGRAMReports necessary to comply with the safety programare prescribed in AR 385-40.

2-8. DESTRUCTION OF ARMY MATERIALTO PREVENT ENEMY USE.For information concerning destruction of Army materialto prevent enemy use, refer to TM 750-244-1-5.

2-9. FORMS AND RECORDS.Army aviators flight record and helicopter maintenancerecords which are to be used by crewmembers are pre-scribed in DA PAM 738-751 and TM 55-1500-342-23.

2-10. EXPLANATION OF CHANGE SYM-BOLS.Changes, except as noted below, to the text and tables,including new material on added pages, are indicated bya vertical line in the outer margin extending close to theentire area of the material affected; exception: pageswith emergency markings, which consist of black diago-nal lines around three edges, may have the vertical lineor change symbol placed along the inner margins. Sym-bols show current changes only. A miniature pointinghand symbol is used to denote a change to an illustration.However, a vertical line in the outer margin, rather thanminiature pointing hands, is utilized when there havebeen extensive changes to an illustration. Change sym-bols are utilized to indicate changes in the following:

a. Introductory material.b. Indexes and tabular data where the change cannot

be identified.c. Blank space resulting from the deletion of text, an

illustration, or a table.d. Correction of minor inaccuracies, such as spelling,

punctuation, relocation of material, etc., unless such

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1-4

correction changes the meaning of instructive informa-tion and procedures.

2-11. HELICOPTER DESIGNATION SYS-TEM.The designation system prescribed by AR 70-50 is usedin helicopter designations as follows:

Series SymbolDesign Number

Helicopter (Basic Mission)Attack (Modified Mission)

1H -A F

2-12. SERIES AND EFFECTIVITY CODES.

Designator symbols are used in conjunction with textcontents, text headings and illustration titles to show lim-ited effectivity of the material. One or more designatorsymbols may follow a text heading or illustration title toindicate proper effectivity, unless the material applies toall series and configurations within the manual. Designa-tor symbol CN C-Nite precedes procedural steps inChapters 4, 8, and 9 and other areas to indicate effectiv-ity. If the material applies to all series and configurations,no designator symbols will be used. Where practical, de-scriptive information is condensed and combined for allmodels to avoid duplication.

Designator symbols for different types of main rotorblades are: B540 for the Bell main rotor blade and K747for the Kaman main rotor blade.

2-13. USE OF SHALL, WILL, SHOULD, ANDMAY.

Use shall whenever it is necessary to express a provi-sion that is binding. Use should and may wheneverit is necessary to express non-mandatory provisions.Will may be used to express a declaration of purpose.

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CHAPTER 2 HELICOPTER AND SYSTEMS DESCRIPTION AND OPERATION

SECTION I. HELICOPTER

2-1. GENERAL DESCRIPTION.The AH-1F helicopter is a tandem seat, two place (pilotand gunner), single engine aerial weapon platform.

a. Fuselage. The fuselage (forward section) em-ploys aluminum alloy skins and aluminum, titanium andfiberglass honeycomb panel construction. Honeycombdeck panels and bulkheads attached to two main beamsproduce a box-beam structure. These beams make upthe primary structure and provide support for the cockpit,landing gear, wings, engine, pylon assembly, fuel cells,and tailboom. The nose section incorporates the turretsystem and telescopic sight unit.

b. Wing. The fixed cantilever wings have a span of129 inches (including tip) and a mean chord of 30 inches.The wings provide additional lift and support to the wingstores pylon. Each wing has two pylons. The inboard py-lons are fixed and the outboard pylons are articulated byhydraulic actuators. An ejector rack is attached to eachpylon. Both inboard and outboard pylons will each sup-port 670 pounds of weight.

c. Tailboom. The tailboom (aft section) is a taperedsemimonocoque structure attached to the forward sec-tion by four bolts. The tailboom supports the camberedfin, tail skid, elevators, tail rotor and tail rotor drive sys-tem.

d. Main Rotor Blades.

(1) B540 The main rotor blades are metal,bonded assemblies. Each blade is attached in the hubwith a retaining bolt assembly and is held in alignment byadjustable drag braces.

(2) K747 The main rotor blades are glass fiberepoxy resin bonded assemblies with a rubber erosion

guard. The skin is basket weave which will not be assmooth as a metal blade. Each blade is attached in thehub with a retaining bolt assembly and is held in align-ment by adjustable drag braces.

e. Weight Classification. The weight classificationof this helicopter is Class 2. (Refer to Chapter 6.)

f. Controls and Indicators. Refer to applicablesystem for descriptive information.

2-2. GENERAL ARRANGEMENT.Figure 2-1 shows the general arrangement of the itemswhich are referred to in the exterior check paragraph ofChapter 8, Section 11.

2-3. PRINCIPAL DIMENSIONS.Figure 2-2 shows the principal dimensions of the heli-copter to the nearest inch.

2-4. TURNING RADIUS.Figure 2-3 shows the minimum turning radius of the heli-copter.

2-5. MAIN DIFFERENCES.The main differences between the AH-1F and CN is theTSU FLIR Subsystem M65.

2-6. CREW COMPARTMENT DIAGRAMS.The upper forward portion between the fuselage is thecrew compartment. Tandem seating is provided with thepilot elevated in the rear seat.

a. Pilot Station. Figure 2-4 shows the location.b. Gunner Station. Figure 2-5 shows the locations

of equipment in the gunner station.

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BOTTOMVIEW

TurretSearchlightLower cutter assemblyForward fuel cell drain doorAft fuel cell drain doorVentChin cutter assemblyTail rotorSynchronized elevatorIR jammerAnticollision lightPitot tubeUpper cutter assemblyCanopyPitot doorBattery compartmentMain rotor blades and hubADSTSUSkidTransmission compartmentEngine compartmentGPU receptacleALT ReceiverSkid landing lightNGV position lights

1.2.2A.3.4.5.5A.6.7.8.9.10.10A.11.12.13.14.15.16.17.18.19.20.20A.20B.20C.

MS018087

Figure 2-1. General Arrangement (Typical) (Sheet 1 of 2)

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2-3

DeflectorChannelUpper cutter assemblyEngine inlet shieldsLeft wing position light (red)PylonsGunner door latchTurretSearchlight42 degree gearbox oil sight glassEngine air inlet-right: (left opposite)DeletedFuel filler cap

21.21A.

22.22A23.24.25.26.27.28.29.30.31.

32.33.34.35.36.37.38.39.40.41.42.43.

Ground receptacleRight static port (left opposite)DeletedPilot door latchRight wing position light (green)Right tail position light (white) (left opposite)90 Degree gearbox oil sight glassCountermeasures set, transmit ant.Countermeasures set, receive ant.Laser detecting set, sensor unitGPS receive ant.AIM-1/EXL laser

MS018088

Figure 2-1. General Arrangement (Typical) (Sheet 2 of 2)

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2-4

MS018089

Figure 2-2. Principal Dimensions - Airframe

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2-5

MS018090

Figure 2-3. Turning Radius (Typical)

2-7. LANDING GEAR.a. Main Landing Gear. The main landing gear con-

sists of two aluminum lateral mounted arched cross-tubes and two aluminum longitudinal skid tubes attachedto the cross tubes. Each crosstube is enclosed in a fiber-glass fairing for aerodynamic purposes. Each skid tubehas a steel skid shoe on the bottom to minimize skidwear.

b. Tail Skid. The steel tubular type tail skid isinstalled on the aft end of the tailboom to protect the tailrotor blades during tail-low landing.

2-8. INSTRUMENTS AND CONTROLS.a. Pilot Instrument Panel. Figure 2-6 shows the

locations of instruments, switches, panels, and decals inthe pilot instrument panel.

b. Gunner Instrument Panel. Figure 2-7 showsthe locations of instruments, switches, panels, and de-cals in the gunner instrument panel.

c. Other Instruments and Controls. These itemsare shown in the chapter/section which describes theirrelated systems.

2-9. CANOPY.The canopy is the transparent panels on the upper por-tion of the fuselage which encloses the crew compart-ment. The canopy consists of a three piece windshieldextending from the nose of the helicopter (over the gun-ner and pilot heads) to the pylon, the gunner door and pi-lot window on the left side, and the gunner window andpilot door on the right side. The canopy removal systemis used to remove the pilot and gunner windows anddoors during emergencies. The system is covered inChapter 2, Section II.

2-10. PERSONNEL DOORS.Two access doors are hinged on top and swing outwardand up to provide access. The doors have gas operatedstruts that will hold the doors in the full open position witha force of approximately 70 pounds.

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2-6

MS018091

Figure 2-4. Pilot Station Diagram (Typical)

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2-7

MS018092

Figure 2-5. Gunner Station Diagram (Typical)

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2-8

MS018093

Figure 2-6. Pilot Instrument and Control Panel

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MS018094

Figure 2-7. Gunner Instrument and Control Panel

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2-11. SEATS.a. Construction. The seats, side-shoulder panels,

and head protective panels are of armor material whichprovides protection. Both seats are equipped with con-toured seat cushions and back supports made of foamand open mesh for vibration attenuation and crew com-fort.

b. Pilot Seat. The pilot seat is vertically adjustablenonreclining type. The vertical adjustment is reclined at15 degrees. The vertical height adjustable handle(Figure 2-8) is under the left side of the seat. The seatis equipped with a lap safety belt and inertia reel shoulderharness.

c. Gunner Seat. The gunner seat is a fixed seat(non-adjustable and nonreclining). The seat is equippedwith a lap safety belt and inertia reel shoulder harness.The seat also has arm rests.

d. Inertia Reel Shoulder Harness. An inertia reelshoulder harness is incorporated in the pilot and gunnerseats with a manual lock-unlock control handle(Figure 2-8). The handles are located to left front of eachseat. With the control in the unlocked position, the reelcable will extend allowing the occupant to lean forward;however, the reel will automatically lock when helicopterencounters an impact force of two to three g decelera-tion. Locking of the reel can be accomplished from anyposition and the reel will automatically take up the slackin the harness. To release the lock, it is necessary to leanback slightly to release tension on the lock and then un-lock position. It is possible to have pressure against theseat back whereby no additional movement can be ac-complished and the lock cannot be released. If this con-dition occurs, it will be necessary to loosen shoulder har-ness. Manual locking of the reel should be accomplishedfor emergency landings.

SECTION II. EMERGENCY EQUIPMENT

2-12. PORTABLE FIRE EXTINGUISHER.

A portable hand-operated fire extinguisher is located for-ward of the gunner seat (Figure 9-1).

2-13. FIRST AID KIT.

An aeronautical type first aid kit is located behind the pilotseat (Figure 9-1).

2-14. SURVIVAL KIT.

Aircraft Modular Survival System (AMSS) AH-1 tow tubesurvival kit can be installed on the aircraft. Refer to TM1-1680-354-10 for fabrication instructions and limita-tions.

NOTE

The preferred installation position forthe AMSS tow survival kit is the upperright and/or left side outboard positionof the tow launcher. However, if thesepositions are occupied by training de-vices (i.e., air to ground engagementsimulator/air defense (AGES/AD) thenthe AMSS tow survival kit can beinstalled in any of the remaining posi-tions of the tow launchers.

2-15. CANOPY REMOVAL SYSTEM.

WARNING

Debris may be expelled 50 feet outwardwhen system is actuated.

Cutting assemblies are mounted in the pilot and gunnerdoors and windows frames. The linear explosive is con-tained with the cutting assemblies. The cutting assem-blies are controlled by the pilot or gunner arming/firingmechanisms. Rotating the arming/firing mechanismhandle 90 degrees counterclockwise (torque required 6to 12 inch-pounds) will arm the cutting assemblies. Pull-ing the handle (20 to 35 pounds tension) will fire the per-cussion primer causing the cutting assemblies to be det-onated. The explosive force will be outward and removetwo windows and two doors from the helicopter simulta-neously. If handle has been rotated but not pulled, thehandle can be rotated clockwise and the safety pininstalled DA Form 2408-13-1 entry required. Refer toChapter 9 for emergency procedure and Figure 9-1 forequipment location.

2-16. WING STORES JETTISON.

Wing stores jettison capability is provided by explosivecartridges installed at each wing stores pylon.

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2-11

MS018095

Figure 2-8. Pilot Seat Installation (Typical)

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2-12

SECTION III. ENGINE AND RELATED SYSTEMS

2-17. ENGINE.

The helicopter is equipped with a T53-L-703 engine(Figure 2-9). The engine, in this installation, is deratedby limitation of the helicopter transmission to 100%(1290 SHP) torque for 30 minutes and 88% (1134 SHP)torque for continuous operation at 100% rpm. The en-gine compartment is cooled by ram and ambient air.

2-18. ENGINE PROTECTION.

Armor material is located on the left and right enginecompartment doors to provide armor protection for theengine compressor, fuel control, oil filter, and fuel filter.

2-19. AIR INDUCTION SYSTEM.

Ambient air enters the transmission compartment doorair inlet, then is routed through the improved particle sep-arator. The particle separator prevents debris and dirtparticles from entering the engine air inlet and causing in-gestion damage to the engine. Bleed air from the engineis used to purge the separator and eject the particle over-board.

2-20. ENGINE INLET ANTI-ICING/DEICINGSYSTEM.

WARNING

The system will not deice or prevent ic-ing of the particle separator. A powerloss will occur if the formation of ice inthe particle separator obstructs the flowof ambient air to the engine.

a. Description. The system prevents ice fromforming in the engine air inlet. The system consists of ahot air solenoid valve on the engine, controlled by the pi-lot or gunner ENG DEICE switch (Figure 2-10 andFigure 2-12) powered by the dc essential bus, and pro-tected by the ENG DEICE circuit breaker.

b. Operation. If ice accumulation is suspected, thepilot or gunner ENG DEICE switch is placed in the DEICEposition. This action causes the hot air solenoid valve toroute engine bleed air to the engine air inlet. A rise in theturbine gas temperature (TGT) will occur when the pilotor gunner ENG DEICE switch is in the DEICE position.Deice operation will become continuous if the hot air so-lenoid valve (ENG DEICE) circuit fails or if ENG DEICEcircuit breaker is out (extended).

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2-13

Figure 2-9. Power Plant Installation - (Sheet 1 or 4)

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2-14

View B*

*After incorporation of MWO 55-1520-236-50-12.

Left Side

MS018097

Figure 2-9. Power Plant Installation - (Sheet 2 of 4)

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2-15

Figure 2-9. Power Plant Installation - (Sheet 3 of 4)

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2-16

View A*

*After incorporation of MWO 55-1520-236-50-12.

Right Side

MS018099

Figure 2-9. Power Plant Installation - (Sheet 4 of 4)

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2-17

MS018100

Figure 2-10. Pilot Engine Control Panel

2-21. ENGINE FUEL CONTROL SYSTEM

a. Engine Mounted Component. The fuel con-trol assembly is mounted on the left side of the engine.This unit is controlled by the pilot or gunner throttle andGOV switch. The assembly consists of a metering sec-tion, a computer section, and an overspeed governor.The metering section pumps fuel to the engine. Thecomputer section determines the rate of fuel delivery.The overspeed governor maintains a constant N2 rpm.

b. Crew Controls.

(1) Throttles. Setting the pilot or gunnerthrottle to the full open position allows the engine to oper-ate up to full power available. Rotating the throttle backtoward idle position decreases the allowable N2 andpower which, if below that demanded by collective pitchinput, results in proportional N2 speed decrease. Rotat-ing the throttle past the engine idle stop to the fully closedposition shuts off fuel flow. A solenoid operated idle stopis incorporated to prevent inadvertent throttle closure.The idle stop is controlled by the pilot IDLE STOP RELswitch (Figure 2-15) or the gunner IDLE STOP RE-LEASE switch (Figure 2-12). The engine idle stop re-lease circuit is powered by the dc essential bus and pro-tected by the IDLE STOP SOL circuit breaker. Frictioncan be induced into both throttles by rotating the pilotthrottle friction (Figure 2-15) counterclockwise.

(2) Governor Switches. The pilot or gunnerGOV Switches (Figure 2-11 and Figure 2-12) AUTOposition, permits the overspeed governor to automatical-ly control fuel metering and engine speeds (N1 and N2).The EMER position permits the pilot and gunner tomanually control the engine rpm. The governor circuit ispowered by the dc essential bus and protected by theGOV CONTR circuit breaker.

2-22. IGNITION-STARTER SYSTEM.The pilot ignition-starter trigger switch (Figure 2-15) ispressed and held to start the engine. The switch mustbe released manually when the engine starts or the timelimit expires. The pilot FUEL switch (Figure 2-10) mustbe in the FUEL position and the pilot ignition keylockswitch (Figure 2-6) in the ON position to complete theignition and start fuel circuit. The GEN switch must bein OFF position for normal starting. The circuits are pow-ered by the dc essential bus and protected by the STARTRLY and IGN SOL circuit breakers.

2-23. RPM INCREASE-DECREASE (INCR-DECR) SWITCHES.The pilot RPM INCR-DECR or gunner INC-DECR switch(Figure 2-11 and Figure 2-12) is a three-position, mo-mentary-type switch located in the pilot collective switchbox and gunner miscellaneous control panel. The switchis held forward to increase and aft to decrease the powerturbine speed. The circuit is powered by the dc essentialbus and protected by the GOV CONTR circuit breaker.

2-24. DROOP COMPENSATOR.

A droop compensator maintains engine rpm (N2) aspower demand is increased by the pilot. The compensa-tor is a direct mechanical linkage between the collectivestick and the speed selector lever on the N2 governor.No crew controls are provided or required. The compen-sator will hold N2 rpm to 0.6% when properly rigged.Droop is defined as the speed change in engine rpm (N2)as power is increased from a no-load condition and is aninherent characteristic of the governor system. Withoutthis characteristic, instability would develop as engineoutput is increased resulting in N1 speed overshooting orhunting the value necessary to satisfy the new powercondition. Design droop of the engine governor systemis as much as 4.5 to 6% (flat pitch to full power). If N2power were allowed to droop, other than momentarily,the reduction in rotor speed could become critical.

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2-18

M65/C-NITE TSU FLIR INTENSITY LEVEL SETTING

CONTROL/INDICATOR FUNCTION

ARMT LT RHEOSTAT NVG SW M65/C-NITE FLIR

OFF LT NORM DAY (HIGH)ON LT NORM NIGHT (MED)ON NVG NVG (LOW)

MS018101

Figure 2-11. Gunner MiscellaneousControl Panel (Typical)

2-25. ENGINE OIL SUPPLY SYSTEM.a. Description. The engine oil system is a dry

sump, pressure type, and completely automatic. The oiltank is located in the upper pylon fairing. It will self-seala 30 caliber projectile hole and is equipped with deaera-tion provisions. Oil is gravity fed from tank to engine driv-en oil pump which provides pressure and scavenging forthe system. On helicopters with ODDS, an external oilseparator, with integral chip detector, and a 3-micron oilfilter are installed downstream of the sump.

MS018102Figure 2-12. Gunner Miscellaneous

Control Panel (Typical)

b. Cooling. Engine oil cooling is accomplished byan oil cooler and a bleed air driven turbine fan. The en-gine and transmission oil coolers use the same fan.

c. Switching Action. The pilot ENG OIL BYPswitch (Figure 2-10) AUTO position permits the oil to au-tomatically bypass the oil cooler when the oil tank isapproximately 3.8 quarts low. The OFF position deacti-vates the automatic bypass feature causing the oil topass through the oil cooler regardless of the oil tank level.The switch circuit is powered by the dc essential bus andprotected by the FUEL OIL VALVE circuit breaker.2-26. ENGINE INSTRUMENTS AND INDICA-TORS.

a. Torquemeters. The pilot and gunner torqueme-ters (Figure 2-6 and Figure 2-7) play percent of torque

TM 1-1520-236-10

2-19

imposed upon the engine output shaft. Each torqueme-ter is powered by a separate transducer. The circuit ispowered by the dc essential bus and protected by theTRQ IND circuit breaker.

b. Turbine Gas Temperature (TGT) Indica-tors. The pilot and gunner indicators (Figure 2-6 andFigure 2-7) display the temperature in degrees Celsiusof the air in the first stage N2 nozzle. The circuits arepowered by the dc essential bus and protected by theTGT IND circuit breaker.

c. Dual Tachometers. The pilot and gunnertachometers (Figure 2-6 and Figure 2-7) display the rpmof the engine and main rotor speed in percent. Thetachometer outer scale is marked ENGINE and the innerscale is marked ROTOR. The ENGINE and ROTORneedles are synchronized during normal helicopter op-eration. The circuit is powered by the dc essential busand protected by the TACHDUAL circuit breaker.

d. Gas Producer N1 Tachometers. The pilot andgunner tachometers (Figure 2-6 and Figure 2-7) displaythe rpm of the gas producer turbine speed in percent.The circuit is powered by the dc essential bus and pro-tected by the GAS PROD circuit breaker.

e. Oil Pressure/Temperature Indicator. The pilotindicator (Figure 2-6) displays the psi pressure of the oil

at the pressure side of the oil pump and the temperatureas degrees Celsius of the oil at the engine oil inlet. Thecircuit is powered by the dc essential bus and protectedby the TEMP IND ENG XMSN circuit breaker.

f. Oil Pressure Caution Light. The pilot ENG OILPRESS and gunner ENGINE OIL PRESS (Figure 2-23)will illuminate when the engine oil pressure is below safelimits.

g. Oil Bypass Caution Light. The pilot ENG OILBYPASS caution light (Figure 2-23) illuminates when oiltank level is approximately 3.8 quarts low.

h. Engine Oil Chip Detector Caution Light. Thecaution lights, ENG CHIP in pilot caution panel and CHIPDETECTOR in gunner caution panel, illuminate whensufficient metal chips to complete the electrical circuit arecollected from the engine oil.

i. Fuel Pump Caution Lights. The pilot and gun-ner ENG FUEL PUMP caution lights (Figure 2-23) illumi-nate when either element of the engine driven fuel pumpfails.

j. Governor Caution Lights. The pilot and gunnerGOV EMERG caution lights (Figure 2-23) illuminatewhen the pilot GOV switch is in EMER (Figure 2-10) orwhen the gunner GOV switch is in EMERG(Figure 2-12).

SECTION IV. HELICOPTER FUEL SYSTEM

2-27. FUEL SUPPLY SYSTEM.The helicopter is equipped with a crashworthy fuel sys-tem. The system is designed with the potential of con-taining fuel during a severe, but survivable, crash impactto reduce the possibility of fire. The system has a 50 cali-ber ballistic protection level. Fuel grades and specifica-tions are included in Section XIV.

2-28. CONTROLS AND INDICATORS.a. Fuel Switch. The pilot FUEL switch

(Figure 2-10) FUEL position energizes the forward andaft boost pumps, opens the fuel shutoff valve, and com-pletes the ignition and start fuel circuit. The aft fuel boostpump circuit is powered by the dc nonessential bus. Theother circuits are powered by the dc essential bus. The

circuits are protected by the START RLY, IGN SOL,FUEL/OIL VALVE, FUEL BOOST FWD, and FUELBOOST AFT circuit breakers.

b. Fuel Quantity Indicator. The pilot indicator(Figure 2-6) displays the pounds of fuel in the fuel cells.The circuit is powered by the ac system and protected bythe FUEL QTY circuit breaker.

c. Fuel Quantity Indicator Test Switch. The pilotFUEL GAGE TEST switch (Figure 2-13) is used to testthe fuel quantity indicator operation. Pressing the switchcauses the indicator pointer to move from the actualreading to a lesser reading. Releasing the switch willcause the pointer to return to the actual reading. The cir-cuit is powered by an ac system and protected by theFUEL QTY circuit breaker.

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2-20

NOTE

Low fuel caution systems alert the pilotthat the fuel level in the tank hasreached a specified level (capacity).Differences in fuel densities due to tem-perature and fuel type will vary theweight of the fuel remaining and the ac-tual time the aircraft engine(s) may op-erate. Differences in fuel consumptionrates, aircraft attitude and operationalcondition of the fuel subsystem willalso affect actual time the aircraft en-gine(s) may operate.

d. Low Quantity Caution Lights. The pilot andgunner FUEL LOW caution lights (Figure 2-23) illumi-nate when there is approximately 209 pounds of fuel re-maining. The illumination of this light does not mean afixed time period remains before fuel exhaustion, but isan indication that a low fuel condition exists.

e. Low Fuel Pressure Caution Lights. The pilotFWD FUEL BOOST and AFT FUEL BOOST cautionlights (Figure 2-23) illuminate when the boost pumps inthe forward/aft fuel cell fail.

f. Fuel Filter Caution LIghts. The pilot and gunnerFUEL FILTER caution lights (Figure 2-23) illuminatewhen the filter in the fuel supply line becomes partiallyobstructed.

MS018103

Figure 2-13. Pilot Miscellaneous Control Panel

SECTION V. FLIGHT CONTROLS

2-29. DESCRIPTION.The flight control system is a positive mechanical type,actuated by cyclic, collective, and tail rotor controls.Complete controls are provided for both pilot and gunner.The gunner controls are slaved to the pilot controls. Thesystem includes a cyclic system, a collective control sys-tem, a tail rotor system, a force trim system, and a stabil-ity and control augmentation system (SCAS).

2-30. CYCLIC CONTROL SYSTEM.The pilot and gunner cyclic sticks (Figure 2-14) have abuilt-in operating friction. The cyclic control movementsare not mixed, but are transmitted directly to the swash-plate. The longitudinal cyclic control linkage is routedfrom the cyclic stick through the SCAS actuator, the dualboost hydraulic actuator to the right horn of the fixedswashplate ring. The lateral is similarly routed to the lefthorn. Control feel is provided by the force trim units.The fore and aft movement also changes the synchro-nized elevator (Figure 2-1) attitude to assist controllabili-ty and lengthen c.g. range.

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2-21

Figure 2-14. Pilot and Gunner CyclicControl Stick

2-31. COLLECTIVE CONTROL SYSTEM.The pilot and gunner collective pitch controls(Figure 2-15) are located on the left side of the pilot andgunner seats and control vertical mode of flight. Movingthe stick up or down changes the angle of attack and liftdeveloped by the main rotor resulting in the ascent or de-scent of the helicopter. The collective assembly consistsof a collective stick, with adjustable friction system (pilotonly), twist grip-type throttle with friction adjuster, andswitch box assembly (pilot only). The switch box assem-bly incorporates the ignition starter switch, rpm increase-decrease switch, jettison, searchlight switches, wire cutswitch, and idle stop release switch. A collective holddown strap is provided for the pilot collective.

2-32. TAIL ROTOR CONTROL SYSTEM.Pushing a pedal changes the pitch of the tail rotor result-ing in directional control and is used to pivot the helicop-ter on its own vertical axis and trim the helicopter in flight.A pedal adjuster is provided to adjust the pedal distancefor individual comfort. Heel rests are provided for thegunner to prevent inadvertent pedal operation.

2-33. FORCE TRIM SYSTEM.The system incorporates a magnetic brake and forcegradient in the cyclic and directional control systems toprovide artificial feel into the systems. Also, it providesa means to trim the controls. Placing the FORCE TRIMswitch (Figure 2-10) in the FORCE TRIM position will in-duce artificial feel into the systems. Depressing the cy-clic stick force trim switch (Figure 2-14) will cause themagnetic brake and force gradient to be repositioned tocorrespond to the positions of the cyclic stick and pedalsthus providing trim. The system is powered by the dc es-sential bus and protected by the FORCE TRIM circuitbreaker.

2-34. STABILITY AND CONTROL AUG-MENTATION SYSTEM (SCAS).

a. Description. The SCAS is a three-axis, limitedauthority rate reference augmentation system. TheSCAS cancels undesired motion of the helicopter duringflight. This is accomplished by inducing an electrical in-put into the flight control system to augment the pilot me-chanical input.

Figure 2-15. Pilot Collective Control Stickb. Control Panel. The SCAS control panel

(Figure 2-16) contains a POWER switch for applying dc(essential bus) and ac power to the system. The circuitsare protected by the SCAS POWER dc and SCAS PWRac circuit breakers. The panel also contains three chan-nel engage switches which energize electric solenoid

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2-22

valves controlling hydraulic pressure to the system. Thepanel has three amber colored NO-GO lights, one asso-ciated with each PITCH, ROLL, and YAW channel en-gage switch. These lights are illuminated during the war-mup to indicate the presence of current in eachassociated channel actuator. Should an engagement beattempted during this warmup period, the actuator maymake an abrupt input to the flight controls at the momentof engagement. When engagement is made, the NO-GO lights are locked out of the circuit and do not operateas malfunction indicators. Disengaging a channel, how-ever, restores the associated light to operation. The NO-GO lights have a built-in press-to-test feature for ensur-ing that the indicator is operational, but this feature worksonly prior to channel engagement.

c. SCAS (SAS) Release Switch. The cyclic gripmounted switch (Figure 2-14) is used to disengage thepitch, roll, and yaw channels simultaneously. The chan-nels are re-engaged by the PITCH, ROLL, and YAWswitches on the SCAS control panel.

d. RECOIL COMP Switch. The RECOIL COMPswitch is a three position switch (LO-MED-HI) located onthe right side of the pilot instrument panel. It may be usedto vary the magnitude of the signals from the ArmamentCompensation Unit to the SCAS to compensate for alower/higher than average M197 firing rate.

Figure 2-16. Pilot SCAS Control Panel

SECTION VI. HYDRAULIC SYSTEMS

2-35. DESCRIPTION.

The hydraulic system is a dual system (No.1 and No. 2system) used to minimize the force required by the pilotto move the cyclic, collective, and pedal controls. TheNo. 1 and No. 2 systems are installed to provide maxi-mum separation to reduce the probability of a single pro-jectile from incapacitating both systems.

2-36. HYDRAULIC SYSTEM NO. 1.

The No. 1 system provides hydraulic power to the cycliccontrols, collective controls, pedal controls, and SCASyaw controls. The No. 1 system is located on the left sideof the helicopter.

2-37. HYDRAULIC SYSTEM NO. 2.

The No. 2 system provides hydraulic power to the cycliccontrols, collective controls, SCAS pitch and roll con-trols, articulated wing pylons. The No. 2 system is lo-cated on the right side of the helicopter.

2-38. TEST SWITCH.

The pilot HYD TEST switch (Figure 2-10) is used to testthe No. 1 and No. 2 hydraulic systems. Holding theswitch in the SYS 1 position will cause the No. 1 systemto be the only system supplying hydraulic pressure. Sim-ilar action occurs when the switch is held in the SYS 2position.

2-39. RESERVOIR FLUID SIGHT GASSES.The No. 1 and No. 2 reservoirs are provided with a fluidsight glass. Both sight glasses can be seen only from theleft hydraulic compartment door.

2-40. FILTER INDICATORS.The No. 1 and No. 2 pressure and return filters are pro-vided with a differential pressure indicator. The red indi-cator pops out when the filter needs changing or duringcold weather operation.

2-41. LOW PRESSURE CAUTION LIGHTS.The pilot NO. 1 HYD PRESS and NO. 2 HYD PRESS,and gunner #1 HYD PRESS and #2 HYD PRESS cautionlights (Figure 2-23) will illuminate when hydraulic pres-sure is below safe limits.

2-42. ELECTRICAL CIRCUIT.The hydraulic electrical circuit is powered by the dc es-sential bus and protected by the HYD CONTR circuitbreaker.

2-43. EMERGENCY HYDRAULIC SYSTEM.The emergency hydraulic system serves two functions.It provides hydraulic power to outboard pylons for bore-sighting, or to the collective pitch control if both hydraulicsystems fail. The system is controlled by the EMER HYDPUMP switches (Figure 2-7 and Figure 2-13) poweredby the dc essential bus and protected by the EMER HYDPUMP circuit breaker.

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2-44. ARMAMENT HYDRAULIC SYSTEM.The TOW missile system is powered by the No. 2 systemand is used to position the outboard articulated wing py-lons during TOW missile operations. The system is con-

trolled by the TOW missile controls. The system electri-cal circuits are powered by the dc essential bus and theac system. The circuits are protected by the HYDCONTR, ac TMS PWR, and SECU PWR circuit break-ers.

SECTION VII. POWER TRAIN SYSTEM

2-45. TRANSMISSION.The transmission transfers engine power to the main ro-tor through the mast assembly and to the tail rotorthrough a series of driveshafts and gearboxes. Thetransmission has a self-contained pressure oil system.The oil is cooled by an oil cooler and bleed air turbine fan.The transmission and engine oil coolers use the samefan. The oil system has an automatic bypass systemwhich causes the oil to bypass the cooler when a leak issensed in the oil cooler circuit. Two oil level sightglasses, an oil fill cap, and a magnetic chip detector areprovided. On helicopters with ODDS, a full-flow debrismonitor with integral chip detector replaces an integral oilfilter and a 3-micron filter replaces a 25-micron externalfilter.

2-46. GEAR BOXES.a. Intermediate Gearbox - 42 Degree. The gear-

box is located at the base of the vertical fin (Figure 2-1).It provides a 42 degree change of direction of the tail rotordriveshaft. The gearbox has a self-contained wet sumpoil system. An oil level sight glass, a filler cap, and a mag-netic chip detector are provided.

b. Tail Rotor Gearbox - 90 Degree. The gearbox islocated near the top of the vertical fin (Figure 2-1). It pro-vides a 90 degree change of direction of the tail rotor dri-veshaft. The gearbox has a self-contained wet sump oilsystem. An oil level sight glass, a filler cap, and a mag-netic chip detector are provided.

2-47. DRIVESHAFTS.a. Main Driveshaft. The main driveshaft connects

the engine output shaft to the transmission input drivequill.

b. Tail Rotor Driveshaft. The tail rotor driveshaftconsists of five driveshafts and three hanger bearing as-

semblies. The assemblies and the 42 and 90 degreegearboxes connect the transmission tail rotor drive quillto the tail rotor.

2-48. INDICATORS AND CAUTION LIGHTS.a. Transmission Oil Pressure/Temperature Indi-

cator (Figure 2-6). The pilot indictor displays the pres-sure in psi and temperature in degrees Celsius of thetransmission oil. The electrical circuit is powered by thedc essential bus and protected by the INDTEMP ENG/XMSN circuit breaker.

b. Transmission Oil Low Pressure CautionLights. The TRANS OIL PRESS caution lights(Figure 2-23) illuminate when the transmission oil pres-sure drops below safe limits.

c. Transmission Oil Hot Caution Lights. TheTRANS OIL HOT caution lights (figure 2-23) illuminatewhen the transmission oil temperature exceeds the safelimits.

d. Transmission and Gearboxes Chip Detectors.(1) The pilot chip detector caution lights

(Figure 2-23) illuminate when sufficient metal chips aredetected in the 42 degree gearbox, 90 degree gearbox,or the transmission oil. On aircraft equipped with Oil De-bris Detection System (ODDS), when a chip gap isbridged by conductive particles, a power module pro-vides an electrical pulse which burns away normal wearparticles.

(2) The pilot caution lights are worded: 42CHIP, 90 CHIP, and TRANS CHIP for the respectiveunit.

(3) The gunner chip detector caution light(Figure 2-23) will only illuminate CHIP DETECTOR.This caution light does not identify the contaminatedcomponent.

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SECTION VIII. MAIN AND TAIL ROTORS

2-49. MAIN ROTOR.a. Description.

(1) B540 The main rotor blades are metal,bonded assemblies. Each blade is attached in the hubwith a retaining bolt assembly and is held in alignment byadjustable drag braces.

(2) K747 The main rotor blades are glass fiberepoxy resin bonded assemblies with a rubber erosionguard. The skin is basket weave which will not be assmooth as a metal blade. Each blade is attached in thehub with a retaining bolt assembly and is held in align-ment by adjustable drag braces.

(3) The main rotor is driven by the mast whichis connected to the transmission. The rotor rpm is gov-erned by the engine rpm during powered flight. The rotortip path plane is controlled by the cyclic stick. The rotorpitch is controlled by the collective stick.

b. Hub Moment Spring. As an aid in controlling ro-tor flapping, a hub moment spring kit has been installedin the rotor system. Two nonlinear elastomeric springsare attached to a support affixed to the mast. The hubmoment springs provide an additional margin of safety inthe event of an inadvertent excursion of the helicopterbeyond the approved flight envelope.

c. RPM Indicators. The pilot and gunner indicatorsare part of the dual tachometers (Figure 2-6 andFigure 2-7). The tachometer inner scale displays per-cent rotor rpm.

2-50. TAIL ROTOR.

The tail rotor is driven by the 90 degree gearbox whichis connected to the transmission by the tail rotor drive-shaft assemblies and the 42 degree gearbox. The rotorrpm is governed by the transmission rpm. The rotorblade pitch is controlled by the pedals.

SECTION IX. UTILITY SYSTEM

2-51. PITOT TUBE/AIR DATA SYSTEMHEATER.

a. Pitot Tube Heater. The pitot tube (Figure 2-1) isequipped with an electrical heater. The PITOT/ADSswitch (Figure 2-17) in HTR position activates the heaterin the tube and prevents ice from accumulating in the pi-tot tube. The OFF position deactivates the heater. Theelectrical circuit is powered by the dc nonessential busand protected by the PITOT HTR circuit breaker.

b. Air Data System (ADS) Heater. The air datasystem sensing head contains an electrical heater. The

pilot PITOT/ADS switch (Figure 2-17) in the HTR posi-tion activates the ADS heater, in addition to the pitot tubeheater, and prevents ice from accumulating in the pitottube and air data system. The OFF position deactivatesthe heater. The system is powered by the dc nonessen-tial bus, ac system, and protected by the ADS PWR andADS ANTI-ICE circuit breaker.

2-52. CANOPY DEFROSTING, DEICINGAND RAIN REMOVAL SYSTEMS.These systems are considered to be part of the environ-mental control system. See Section X of this chapter.

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MS018107

SWITCH/CONTROL POSITION FUNCTION

COOL/WARM COOL to WARM Controls temperature (35F - 180F) in the crewcompartment when the ECU/RAIN RMV switch isin the ECU position.

ECU/RAIN RMV RAIN RMV Removes rain from canopy. Only ambient air ven-tilation enters the crew compartment.

May be used to defrost, defog, or deice the for-ward area of the canopy.

ECU Heats or cools the crew compartment.

OFF Ambient air ventilation enters the crew compart-ment.

HEAT OR VENT AIRPULL

OUT Directs maximum air to the defrost slots, air vents,and pilot/gunner seat cushions.

IN Directs maximum air to the pilot seat cushion.

Air Vent Open/Closed Controls the volume/direction of air to the crewcompartment.

Defrost Slot Lever Aft (Open)/Forward(closed)

Controls the volume of air directed to the innersurfaces of the canopy for defogging, defrosting,and deicing.

Figure 2-17. ECS Controls (Typical)

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SECTION X. HEATING, VENTILATION, COOLING, ENVIRONMENTAL CONTROL UNIT

2-53. ENVIRONMENTAL CONTROL SYS-TEM (ECS).

a. ECS Functions.

(1) Heats/cools the crew compartment.(2) Removes moisture from the air supplied to

the crew compartment.

(3) Defrosts, defogs, and deices the canopy.(4) Rain removal.(5) Provides ambient air ventilation to the crew

compartment.

b. ECS Power Source. The ECS is electrically con-trolled and engine bleed air powered. The circuit is pow-ered by the dc nonessential bus and protected by theECS CONTR circuit breaker.

c. ECS Controls.NOTE

Under certain conditions a plume maybe observed at the air vents in the crewcompartment. The plume may appearto be smoke, but is actually condensa-tion.

(1) The pilot ECS controls and their functionsare shown on Figure 2-17.

(2) Adjustable air vents are provided for the pi-lot and gunner to control the volume and direction of theair entering the crew compartment.

(3) Air entering the pilot and gunner seat cush-ions is controlled by a valve at the top of each seat.

(4) Rain removal. The rain removal does notremove rain in flight.

SECTION XI. ELECTRICAL POWER SUPPLY AND DISTRIBUTION SYSTEM

2-54. DC AND AC POWER DISTRIBUTION.

Figure 2-18 depicts the general schematic of the dc andac power distribution system. The dc power is suppliedby the battery, starter-generator, alternator through thetransformer rectifier unit (TRU), or an external powersource through the external power receptacle. The 115vac power is supplied by the alternator or inverter. The26 vac power is supplied by the 28 vac transformer.

2-55. BATTERY.

The battery (Figure 2-18) supplies 24 vdc power to thepower distribution system when the starter-generator,TRU and the external power receptacle are not in opera-tion.

2-56. STARTER-GENERATOR.The starter-generator is mounted on and driven by theengine. The starter-generator supplies 28 vdc power tothe power distribution system and recharges the battery.

2-57. ALTERNATOR.A 10kVA alternator is mounted on and driven by thetransmission. The alternator supplies 115 vac 3-phasepower to the ac buses and transformer rectifier unit(TRU).2-58. TRANSFORMER RECTIFIER UNIT(TRU).The transformer rectifier unit converts ac (from alterna-tor) to 28 vdc, thereby powering the TRUbus.

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MS018108

Figure 2-18. DC and AC Power Distribution Schematic (Sheet 1 of 2)

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MS018109

Figure 2-18. DC and AC Power Distribution Schematic (Sheet 2 of 2)

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2-59. EXTERNAL POWER RECEPTACLE.

This external power receptacle (Figure 2-1) transmitsthe ground power unit 28 VDC power to the power dis-tribution system. A 7.5 KW GPU is recommended for ex-ternal starts.

2-60. GUNNER ELECTRICAL POWERCONTROL.

The gunner ELEC PWR - EMERG OFF switch(Figure 2-12) in the ELEC PWR position permits the pilotto control the electrical system. The switch in EMERGOFF position removes all power from the electrical sys-tem.

2-61. PILOT DC POWER INDICATORS ANDCONTROLS.

a. Battery Switch. The BATTERY switch(Figure 2-19) START or RUN position permits the bat-tery to supply DC power to the power distribution systemor permits the battery to be charged by the starter/gener-ator. The RUN position also activates the inverter. TheOFF position isolates the battery and inverter from thesystems.

b. Generator Switch. The GEN switch(Figure 2-19) ON position permits the starter-generatorto supply DC power to the PWR XFR BUS. The RESETposition will reset the starter-generator. When the switchis released, it will return to OFF. The OFF position iso-lates the generator from the system and allows the start-er-generator to function as a starter. The circuit is pro-tected by the GEN BUS RESET and GEN FIELD circuitbreakers.

c. Nonessential Bus Switch. The NONESNTLBUS switch (Figure 2-19) functions only when the bat-tery is the sole source of DC power to the helicopter. TheNORMAL position supplies DC power to the essentialDC bus. The manual position supplies DC power to boththe essential and non-essential buses. When either thegenerator or TRU are operating, the essential and non-essential buses both receive DC power regardless of theposition of the non-essential bus switch.

d. DC Circuit Breaker Panel. The DC circuit break-ers (Figure 2-20) in the closed position provide circuitprotection for the 28 VDC operated equipment. Thebreakers in the open position deactivates the circuit. Thebreakers will open automatically in the event of a circuitoverload. Each breaker is labeled for the particular cir-cuit it protects. Each applicable breaker is listed in theparagraph describing the equipment it protects.

e. Armament DC Circuit Breakers. The arma-ment DC circuit breakers (Figure 2-20) in the closedposition provide circuit protection for the DC operatedequipment. The breaker in the open position deactivatethe circuit. The breakers will open automatically in theevent of a circuit overload. Each breaker is labeled forthe particular circuit it protects. Each applicable breakeris listed in the paragraph describing the equipment it pro-tects.

f. Volt-Ammeter Indicator. The pilot indicator(Figure 2-26) displays the DC power voltage being sup-plied to the power distribution system. Simultaneousdisplay of DC amperage is displayed only when the start-er-generator is supplying power to the distribution sys-tem. The indicator right scale displays the voltage. Theleft scale displays the amperage. The circuit is poweredby the DC essential bus and protected by the DCVM cir-cuit breaker. There is no means of monitoring amperageload when DC power is supplied by the TRU. Overcharg-ing of the battery or a thermal runaway condition couldoccur with no indication to the pilot.

g. Generator Caution Lights. The pilot and gun-ner DC GEN caution lights (Figure 2-23) illuminate whenthe DC generator fails or when the GEN switch is OFF.

h. External Power Receptacle CautionLight. The pilot EXT PWR caution light (figure 2-23) illu-minates when the external power receptacle door isopen.

2-62. AC POWER INDICATORS AND CON-TROLS.

a. Alternator Switch. The ALTNR switch(Figure 2-19) energizes the alternator to supply power tothe AC buses and transformer rectifier unit (TRU) whenin ON position. It deactivates and/or resets the alternatorwhen in the OFF RESET position. Any time the alterna-tor is inoperative or the ALTNR switch is in OFF RESETposition, the inverter supplies AC power.

b. AC Circuit Breaker Panel. The AC circuit break-ers (Figure 2-20) in the closed position provides circuitprotection for the AC operated equipment. The breakersin the open position deactivate the circuit. The breakerswill open automatically in the event of a circuit overload.Each breaker is labeled for the particular circuit it pro-tects. Each applicable breaker is listed in the paragraphdescribing the equipment it protects.

c. Alternator Caution Light. The pilot and gunnerALTER caution light (Figure 2-23) will illuminate when ro-tor rpm is below 91 percent, the ALTNR switch is in theOFF RESET position, or when the alternator has failed.

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MS018110

Figure 2-19. Pilot Electrical Power Panel

SECTION XII. LIGHTING

2-63. POSITION LIGHTS.a. Standard Position Lights.

(1) General. The position lights consist of theright wing green light, left wing red light, and two tailboomwhite lights (Figure 2-1). The lights are powered by theDC nonessential bus and protected by the POS LT circuitbreaker.

(2) Operation. The pilot POSITION LT(FLASH/OFF/STEADY) switch (Figure 2-21) FLASHposition flashes the four lights off and on. The STEADYposition illuminates the four lights continuously. TheOFF position deactivates the four lights. The pilot POSI-TION LT (BRT/DIM) switch (Figure 2-21) controls thefour lights brightness.

b. NVG Position Lights.(1) General. A covert lighting system, consist-

ing of five infrared NVG position lights, has been pro-vided for use during multi-ship night vision goggle (NVG)operations. The lights are mounted adjacent to the stan-

dard position lights and at the top of the vertical fin(Figure 2-1). The lights are powered by the DC nones-sential bus and protected by the NVG POS LTS circuitbreaker (Figure 2-18 and Figure 2-20).

(2) Operation. The NVG POS LTS (OFF/fiveposition) rotary switch (Figure 2-21) controls the opera-tion of the NVG position lights. Position I activates thelights at minimum intensity. The intensity may be in-creased incrementally by rotating the switch toward BRT.The OFF position deactivates the five NVG positionlights.

2-64. ANTI-COLLISION LIGHT.a. General. The anti-collision light (Figure 2-1) is

powered by the DC nonessential bus and protected bythe ANTI-COLL LT circuit breaker.

b. Operation. The pilot ANTI-COLL LT switch(Figure 2-21) ON position illuminates the anti-collisionlight. The OFF position deactivates the light.

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MS018111

Figure 2-20. Circuit Breaker Panels

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2-65. SEARCH LIGHT/LANDING LIGHT.

a. Searchlight.

(1) General. The searchlight consists of an IRbypass filter and 150 watt sealed beam lamp installed onthe standard search light housing to provide illuminationduring NVG operations under low ambient light condi-tions. The searchlight (Figure 2-1) is powered by the DCessential bus and protected by the SRCH LT PWR circuitbreaker. The searchlight control is powered by the non-essential bus and protected by the SRCH LT CONTR cir-cuit breaker (Figure 2-18 and Figure 2-20).

(2) Operation.

(a) Searchlight Switch. The SRCH LTswitch (Figure 2-15) ON position illuminates the light.The OFF position deactivates the light. The STOW posi-tion retracts the light into the fuselage well.

(b) Searchlight Control Switch. Thesearchlight control switch (Figure 2-15) EXT position ex-tends the light from the fuselage well and moves it for-ward. RETR position moves the light aft. The L/R posi-tion moves the light left and right.

b. Skid Landing Light.

(1) General. A fixed landing light is installedon the left side of the aircraft attached to the forwardlanding gear crosstube (Figure 2-1). This light providesa white light capability for use during night operation with-out NVG. The landing light is powered by the dc essen-tial bus and protected by the SKID LDG LT circuit break-er.

(2) Operation. The SKID LDG LT switch(Figure 2-4) ON position illuminates the light. The OFFposition deactivates the light. The elevation of the land-ing light beam is adjustable on the ground only.

NOTE

The IR filter and 150 watt bulb may beinstalled on the skid landing light withthe 450 watt bulb installed in the stan-dard searchlight housing. This config-uration provides a slewable whitesearchlight and a ground-adjustable IRlight.

2-66. COCKPIT UTILITY LIGHTS.a. General. The pilot (two) and the gunner (one)

utility lights are powered by the dc essential bus and pro-tected by the CKPT LT circuit breaker. The lights aresupplied in various configurations. All configurationshave on-off and bright/dim capabilities and provide NVGcompatible light. Adjustable extensions have been pro-vided for pilot (right) and gunner utility lights. An alter-nate light bracket is provided for the pilot (left) utility light.

NOTEThe cockpit utility light lens selectormust be placed in the white positionin order to provide adequate illumina-tion with NVG filters installed.

b. Operation. The pilot/gunner determines the con-figuration of his light and operates it accordingly.

2-67. PILOT STATION LIGHTING.a. General. The cockpit is illuminated by integral

lights, post lights, flood lights, and bezel lights. The lightsare powered by the dc essential bus and protected by thePLT INST LT circuit breaker.

b. Night Vision Feature. NVG compatibility is pro-vided by using blue-green lighting, in various configura-tions, to illuminate instruments, avionics and control pan-els. The NVG ENBL/OFF switches (Figure 2-21) andLTS switch (Figure 2-14) have been disabled.

c. Operation. The pilot rheostat knobs(Figure 2-21) OFF position deactivates the lights. Thebetween OFF and BRT position controls the brightnessof the instruments, avionics, and control panel lights asfollows:

(1) Console. ROCKETS (RMS), ARMT Con-trol panel, COMM CONT panel, miscellaneous controlpanel, FM radio, VHF AM radio, horizontal situation indi-cator (HSI) control panel left and right console, light rheo-stat control panel APR 39 radar warning, HUD controlpanel and reflex sight controls. The MASTER CAU-TION, RPM and OVERTORQUE lights will dim to a pre-set intensity, when the CAUTION panel (BRIGHT/DIM)switch is in DIM and the CONSOLE rheostat is on. NVGcompatible flip filters have been provided for the MAS-TER CAUTION, RPM, OVERTORQUE, FIRE, andCAUTION panel lights (Figure 2-6). NVG compatible fil-ters are also provided for the ROCKETS control panel(Figure 4-11), APR 39 radar warning (Figure 3-20), andthe switches on the armament (ARMT) panels(Figure 2-6, Figure 2-7, and Figure 4-17).

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MS018112

DISABLED

Figure 2-21. Pilot Light Control Panel

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WARNING

Caution/Warning flip filters are to re-main in the open (unfiltered) positionduring day flight to insure that caution/warning lights are readily visible.

(2) Engine. Fuel quantity, engine tempera-ture/pressure, transmission temperature/pressure, dualtachometer, TGT, volt/ammeter, N1, and torque.

(3) Flight. Airspeed indicator, attitude indica-tor, HSI, vertical speed indicator (VSI), pressure altime-ter, radar altimeter, and clock.

(4) Tactical. Torque, low airpeed attitude indi-cator, HSI, radar altimeter, and clock.

NOTE

With tactical rheostat in the ON posi-tion, only the listed instruments will beilluminated.

2-68. GUNNER STATION LIGHTING.

a. General. The gunner instrument panel is illumi-nated by NVG compatible flood lights. The armamentcontrol panel, (Figure 4-17) is illuminated by an NVGcompatible edgelit panel. The magnetic compass(Figure 2-5) is illuminated by one post light. The lightsare powered by the dc essential bus and protected by theGNR INST LT circuit breaker.

b. Night Vision Feature. NVG compatibility is pro-vided by blue-green lighting, in various configurations toilluminate instruments, avionics and control panels. TheLT NORMAL/NVG switch (Figure 2-12) and LTS switch(Figure 2-14) have been disabled. The LT NORMAL/NVG switch (Figure 2-12) has been reconnected and isused in conjunction with the ARMT LT RHEOSTAT toprovide the FLIR display with three intensity levels(Figure 2-11)

c. Operation. The gunner rheostat knobs(Figure 2-7 and Figure 2-12) OFF position deactivatesthe lights. The between OFF and BRT position controlthe brightness of the instrument, avionics, and controlpanels lights as follows:

(1) Console. CSL LT, WING STORES JETTI-SON and EMER HYDR pump/boresight control panel,COMM CONT Panel, FM radio, ARM STBY, and dopplerNAV CONTROL PANEL. The MASTER CAUTION lightwill dim when the caution panel (BRT/DIM) switch is inDIM and the CSL LT rheostat is on. Doppler MEM/MAL,ARMED/STBY, and PILOT IN CONT lights will dim to apreset intensity when CSL LT rheostat is on. A NVGcompatible flip filter has been provided for the MASTERCAUTION panel lights (Figure 2-7), and the doppler NAVcontrol panel displays (Figure 3-17) have permanent fil-ters installed.

WARNING

Flip filters are to remain in the open (un-filtered) position during day flight to in-sure that the caution lights are readilyvisible.(2) Instrument. INST LT Airspeed indicator,

attitude indicator, pressure altimeter, vertical speed indi-cator (VSI), radio magnetic indicator (RMI), dual tachom-eter TGT. N1. torque and standby compass.

(3) Armament Consoles. ARMT LT: TOWcontrol Panel (TCP), FLIR control panel (FCP), FLIR in-tensity settings. The ARMT LT RHEOSTAT is used inconjunction with the LT NORMAL/NVG switch to providethe FLIR display with three levels (day mode, night modeand NVG mode) of intensity for varying missions/atmo-spheric conditions.

(a) Day Mode - Brightest level generallyused in day operations. This mode provides the greatestobservation ranges.

CAUTIONDay mode operation used for extendedperiods at night/low light conditionsmay cause the CPG to experience oneeye to be bright adapted by FLIR bright-ness, while the other eye night adapted.A flight safety problem could occur ifthe CPG, while operating theM65/C-NITE system, is required to takecontrol of the aircraft to maintain safeflight operations.

(b) Night Mode - Reduced FLIR display in-tensity level generally used in low light conditions. Thismode slightly reduces observation ranges.

(c) NVG Mode - This mode should be uti-lized when CPG is in a heads-up position at night and thepilot is using NVGs which prevents stray light from exitingthe TSU, causing AN/PVS-NVGs to bloom. This modeshould not be used for target detection.

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SECTION XIII. FLIGHT INSTRUMENTS

2-69. AIRSPEED INDICATORS.

The pilot and gunner airspeed indicators (Figure 2-6 andFigure 2-7) display the helicopter indicated airspeed(IAS) in knots. The IAS is obtained by measuring the dif-ference between impact air pressure from the pitot tube(Figure 2-1) and the static air pressure from the staticports (Figure 2-1). IAS is inaccurate due to instrumentand installation errors.

NOTE

IAS below approximately 25 KIAS is in-accurate due to rotor downwash.

2-70. LOW AIRSPEED INDICATOR (LAI)The low airspeed indicator, located in the pilot instrumentpanel, measures and displays low airspeed up to 50knots by horizontal (fore-aft) and vertical (lateral) direc-tion indicators. Airspeed is sensed by the airspeed anddirection sensor. The intersection of the two direction in-dicators is related to the circular scale to obtain resultantairspeed. A three position flag is used to indicate systemoperational system failure or an overrange condition.The primary purpose is to provide windspeed to the FCC.Disregard forward airspeed indication when O/R flag isdisplayed. Refer to Figure 2-22 for airspeed examplesand flag indications.

2-71. PRESSURE ALTIMETERS.

The pilot and gunner altimeters (Figure 2-6 andFigure 2-7) display the helicopter height above sea levelin feet. The altimeters are supplied power by the dc es-sential bus and protected by the ALTM circuit breaker.The altimeter does not provide altitude reporting.

2-72. VERTICAL SPEED INDICATOR.

The pilot and gunner vertical speed indicator (Figure 2-6and Figure 2-7) displays the helicopter ascent and de-scent speed in feet per minute. The indicator is actuatedby the rate of atmospheric pressure change.

2-73. FREE AIR TEMPERATURE (FAT) INDI-CATOR.

The pilot FAT indicator (Figure 2-6) displays the outsideair temperature in degrees Celsius.

2-74. MAGNETIC (STANDBY) COMPASS.The magnetic compass (Figure 2-7) displays the mag-netic heading of the helicopter. A compass correctioncard is attached to the compass.

2-75. RADIO AIDS TO NAVIGATION.The FM radio, automatic direction finder, course indica-tor, and radio magnetic indicator are radio aids to naviga-tion and are covered in Chapter 3.

2-76. MASTER CAUTION SYSTEM.a. Master Caution Lights. The pilot and gunner

MASTER CAUTION lights (Figure 2-23) illuminate whena caution panel light illuminates. This illumination alertsthe pilot and gunner to check caution panels for the spe-cific fault condition.

b. Caution Panels (Figure 2-23).(1) Caution Panel Lights. The pilot and gun-

ner caution panel lights illuminate to identify specific faultconditions. The caution light lettering is readable onlywhen the light illuminates. The light will remain illumi-nated until the fault condition is corrected.

(2) Test/Reset and Test Switches. The pilotcaution panel has a TEST/RESET toggle switch. Thegunner caution panel has a TEST switch. Momentarilyplacing the pilot switch to the test position will cause pilotcaution panel and MASTER CAUTION lights in both pi-lots and gunners station to illuminate. Pressing the gun-ners test switch will cause gunners caution panel to illu-minate. Testing of the system will not change the existingfault condition indications. Momentarily placing the pilotswitch in the RESET position will extinguish and reset thepilot and gunner MASTER CAUTION lights so they willilluminate again should another fault condition occur.

(3) Bright-Dim Switches. The caution panelshave a BRIGHT-DIM (pilot), BRT-DIM (gunner) switch tocontrol the brightness of the panel caution lights and theMASTER CAUTION lights. This switch will not functionif the pilot CONSOLE rheostat (Figure 2-21) of the gun-ner INST LT rheostat (Figure 2-12) is in the OFF position.The caution lights and the MASTER CAUTION lights willbe at full brightness when the pilot/gunner rheostats arein the OFF position.

c. Electrical Circuit. The master caution system ispowered by the dc essential bus and protected by theCAUT LT circuit breaker.

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MS018113

Figure 2-22. Low Airspeed Indicator (LAI)

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2-37

CAUTION PANEL CAUTION PANELWORDING FAULT CONDITION WORDING FAULT CONDITION

ENG OIL PRESS Engine oil pressure below operatingminimum (25 psi).

DC GEN DC generator has failed or GEN switch isOFF.

TRANS OIL PRESS Transmission oil pressure is belowminimum (below 30 psi).

RECT Transformer rectifier unit has failed oralternator is not supplying power.

ENG OIL BYPASS Engine oil bypass switch OFF - Oilsystem level down 3.8 quarts fromfull.

RDRCM INOPGOV EMERG

Radar countermeasures set has failed.Governor switch in emergency position.

Engine oil bypass switch AUTOMATIC- Oil system level down 3.8 quartsfrom full and bypassing cooler.

ALTER Alternator has failed. ALTNER switch isOFF, or ROTOR RPM is below 91% .

GOV EMERG Governor switch in emergency position.TRANS OIL BYPASS Transmission oil bypassing oil cooler. *HUD INOP Head up display has failed.

*FCC INOP Fire control computer has failed.TRANS OIL HOT Transmission oil temperature is at or

above red line.*LASER ARMED LASER ARM switch is in 1st or LAST

position.ENG FUEL PUMP One side and/or both sides of engine

fuel pump producing low pressure. IRCM INOP Indicates system failure or 60 second

cooldown period, then light should goout.

*IFF CODE HOLD Cold hold switch in the hold position.ENG CHIP Metal particles in engine.42 CHIP Metal particles in 42 degree gearbox. IFF CAUTION IFF system inoperative.90 CHIP Metal particles in 90 degree gearbox. EXT PWR External power receptacle door open.TRANS CHIP Metal particles in transmission. #1 HYD PRESS System 1 hydraulic pressure is low.FWD FUEL BOOST Forward fuel boost pump pressure

low (below 5 psi).*EMERG HYD PUMPON

Emergency hydraulic pump is operating.

FUEL FILTER Fuel filter is partially obstructed. *GUN ELEV STOWED Turret weapon is in stowed position.FUEL LOW Low fuel quantity. #2 HYD PRESS System 2 hydraulic pressure is low.AFT FUEL BOOST Aft fuel boost pump pressure low (be-

low 5 psi).CHIP DETECTOR Metal particles in transmission, engine,

42 degree gearbox, or 90 degree gearbox.

*Illuminate aviation green.

Figure 2-23. Pilot and Gunner Caution Panels

TM 1-1520-236-10

2-38

2-77. RPM HIGH-LOW LIMIT WARNINGSYSTEM.The system provides an immediate warning to check in-struments for high or low rotor rpm or low engine rpm.The audio warning will be heard in the pilot and gunnerheadsets. The audio is a varying oscillating frequencystarting low and building up to a high pitch, on for 0.85second interval, then off for 1.25 seconds, then repeatingcycle. The light warning and audio warning functionswhen the following rpm conditions exist:

a. Warning Light Only:

(1) For rotor rpm of 102-104 percent (HighWarning).

(2) For rotor rpm of 93-95 percent (Low Warn-ing).

(3) For engine rpm of 93-95 percent (LowWarning).

(4) Loss of signal (circuit failure) from either ro-tor tachometer generator or power turbine tachometergenerator.

b. Warning Light and Audio Warning SignalCombination:

(1) For rotor rpm of 93-95 percent and enginerpm of 93-95 percent (Low Warning).

(2) Loss of signal (circuit failure) from both rotortachometer generator and power turbine tachometergenerator.

NOTE

It is possible to have an unmodifiedwarning system in the aircraft. On un-modified warning systems,